It is important to note that while we may obtain quasilinear flux ratios from the above procedure, we cannot with linear physics alone obtain the physical fluxes. Throughout the derivation, we have kept the amplitude of the fluctuating potential \(\delta \phi \)  arbitrary. The amplitude \(\phi _0\)  can only be obtained through the use of nonlinear physics by saturating the amplitude. Thus, the complete calculation of these fluxes must be obtained via a saturation rule obtained from a nonlinear computational code, in this case from the Gyrokinetic Electromagnetic Numerical Experiment (GENE) [1]}. This saturation rule is the topic of the next section.
